What You Need:

• A parent or guardian to assist you
• One empty two-liter soda bottle that has been cleaned
  • If you don’t have a two-liter soda bottle, some alternatives are:
    • A funnel and a clear cup or jar, a plastic jug, or a large sports drink bottle.
• A coffee filter
• Tape
• Scissors or a similar cutting tool
• Muddy water made by adding clay or mud to water and then shaking it
  • You can use an old water bottle or any lidded to container to mix up the water.
  • Do not collect muddy water that you find outside as it may not be safe to handle.
• Different types of soil such as clay, sand, gravel, and loam
• Dead leaves
• Fresh leaves and grass
• Optional: Other natural materials that can be found outside such as twigs, pine straw, etc…

What to Do:

• Use scissors or another cutting tool to cut the two-liter bottle about 2/3 up from the top of the bottle. Cut until the two-liter bottle is in two pieces.
  • If the edges where you cut the bottle are rough, you can cover them with tape to help prevent scratches.
• Set the top part of the bottle upside down in the bottom part of the bottle. (See figure below).
  
• Next, you will need to decide how to build your model. You will use the coffee filter, soils, dead leaves, grass, and any other natural materials you collected.
  • First, decide which materials you think will do the best job of filtering the muddy water to make it cleaner. You can use all of the materials or some of the materials. It’s up to you.
  • Second, decide what order the materials need to be layered in your bottle, in order to filter the muddy water.
    • Think about which materials will do the best job of catching the small particles in the muddy water. Those materials are the best ones to use as for your bottom layers.
• Now it’s time to build your model! Put your first layer of material at the bottom of the filter. Then, continue adding each layer of material until you have added all of the materials you want to use.
• Next, remove the bottle cap and place your model back into the bottom half of the two-litter bottle with the nozzle facing down.
• Slowly pour your muddy water into the model and allow the water to flow through your model and into the bottom part of the two-liter bottle.
  • Important: Don’t use all of your muddy water. Keep a sample of the muddy water, so that you can compare it to the water that filters through your model.
• After the water has gone through your model and collected at the bottom of the bottle, compare your filtered water sample to the original muddy water sample.
  • Do you see any changes? Did your filter help clean the water?
    • If your filtered water is cleaner than the original muddy water, congratulations you filtered water just like a wetland!
    • If the water still looks pretty muddy or you want to build a different version of your model, re-design your model and try again!

Did You Know?

Wetlands are very good at removing pollution from the water. Wetlands are a natural buffer zone that can catch and remove pollutants from the water before it flows into rivers, lakes, streams, or other bodies of water.

Water moves slowly through wetlands. Because it is moving slowly, pollutant particles will fall out of the water and get stuck in the soil. Wetland plants can also absorb some of the pollutants out of the water by using their roots and then use the pollutants as plant food.